diff --git a/uc_auction.module b/uc_auction.module
index 1945c31..a39d6d2 100644
--- a/uc_auction.module
+++ b/uc_auction.module
@@ -427,7 +427,7 @@ function uc_auction_form_validate($form, &$form_state) {
       // to the bid increment value.
       // Check that the starting value is sane otherwise.
       // Is it a multiple of the bid increment value?
-      if (!_uc_auction_mod_zero($start)) {
+      if (!_uc_auction_mod_zero($start, $bid_increment)) {
         form_set_error('start_price', t('The start price for this auctioned item should be a multiple of the <em>Bid increment</em> value, which is @inc. Try using @price instead. You may change the <em>Bid increment</em> value on the <em><a href="@aucset">Auction settings</a></em> page.', array('@inc' => uc_currency_format($bid_increment), '@price' => uc_currency_format(ceil($start / $bid_increment) * $bid_increment), '@aucset' => url('admin/store/settings/auction'))));
       }
       // Are things configured such that, with this price, the minimum bid will be